Universidad de Sevilla. Departamento de Física de la Materia Condensada

Fecha:

2014

Publicado en:

Applied Physics Letters, 104 (252405)

Tipo de documento:

Artículo

Resumen:

In recent years, the magnetocaloric effect is studied not only for the search of potential magnetic
refrigerant materials but also for the analysis of critical phenomena. In both cases, the
demagnetizing field might have a notable influence on the results. In this work, we carry out a
systematic study, based on theoretical simulations, of the influence of the demagnetizing factor on
the magnetocaloric properties. On the one hand, we show that demagnetizing factor affects only
slightly the magnetic entropy change (
D
S
M
), reducing its magnitude and shifting the peak to higher
temperatures. On the other hand, it dramatically affects the exponent
n
of field dependence
ð
D
S
M
/
H
n
Þ
at temperatures below the peak. We demonstrate that scaling of the magnetocaloric
curves can be used to remove the influence of the demagnetizing field and, to which extent, critical
exponent determination can be affected. Results of numerical simulations are compared with
experimen...
[Ver más]
In recent years, the magnetocaloric effect is studied not only for the search of potential magnetic
refrigerant materials but also for the analysis of critical phenomena. In both cases, the
demagnetizing field might have a notable influence on the results. In this work, we carry out a
systematic study, based on theoretical simulations, of the influence of the demagnetizing factor on
the magnetocaloric properties. On the one hand, we show that demagnetizing factor affects only
slightly the magnetic entropy change (
D
S
M
), reducing its magnitude and shifting the peak to higher
temperatures. On the other hand, it dramatically affects the exponent
n
of field dependence
ð
D
S
M
/
H
n
Þ
at temperatures below the peak. We demonstrate that scaling of the magnetocaloric
curves can be used to remove the influence of the demagnetizing field and, to which extent, critical
exponent determination can be affected. Results of numerical simulations are compared with
experimental data from a ball milled powder alloy.
[Ver menos]